Time Lag issue with large number of tags

Discussion created by sandeep.narang on Nov 18, 2012
Latest reply on Dec 7, 2012 by Marcos Vainer Loeff

 HI Team




I have a scenario. My application sends the names of around 1000 tags in a list to a service which implements OnValueChange event and send back the updated values of tags to the calling application. The related code snippet is below:

tempList = new PointList();
                                    pList = new PointList();
                                    tagName = string.Empty;

                                    EventFilter objEventFilter = new EventFilter();
                                    foreach (string str in tagList)
                                         tempList = server.GetPoints("tag='" + str + "'", null);



Here pList is consumed in a function which will subscribe to OnValueChange event. The code snippet is :

eventPipe = pList.Data.EventPipe as IEventPipe2;
            eventPipe.PollInterval = 5000;
            myEvents = (_DEventPipeEvents_Event)eventPipe;
            _NewValueEventHandler = new PISDK._DEventPipeEvents_OnNewValueEventHandler(Events_OnNewValue);

            ((_DEventPipeEvents_Event)eventPipe).OnNewValue += (_DEventPipeEvents_OnNewValueEventHandler)_NewValueEventHandler;



The issue which we are facing is that the time taken for getting the points of all the 1000 tags is approx 2 minutes. Now in these 2 minutes, the value of some of the tags is already changed. It causes a serious issue for us in real time environment.


Is ther any work around where we can find the tags for which values were changed in last 2 min and their corresponding new values.




Thanks and Regards